Vehicle air conditioner

ABSTRACT

In an air conditioner constructed to pass an air introduced into an air conditioning unit through an evaporator and a heater core both arranged in the unit, cooler pipes for the evaporator and heater pipes for the heater core are arranged to extend from the same side wall of the air conditioning unit.

TECHNICAL FIELD

This invention generally relates to vehicle air conditioners, andparticularly relates to the technical field for layout structures ofheater pipes and cooler pipes which are disposed around an airconditioning unit.

BACKGROUND ART

There has been conventionally known an exemplary vehicle air conditionerincluding an air conditioning unit with a cooling heat exchanger and aheating heat exchanger and an air blowing unit for blowing air into theair conditioning unit, for example, as disclosed in Japanese UnexaminedPatent Publication No. 9-123748. The air conditioning and air blowingunits are disposed inside of an instrument panel so as to be locatedsubstantially in the widthwise middle of a car and toward thefront-passenger's seat, respectively.

The air conditioning unit is provided at its bottom end side with an airinlet leading from the air blowing unit. An air introduced into the airconditioning unit through the inlet passes through the cooling andheating heat exchangers, which are located above the inlet andsubstantially horizontally arranged one above the other, and is guidedinto the passenger's room through a duct extending from above the heatexchangers. With this air conditioning unit, juxtaposition of two heatexchangers one above the other allows the air conditioning unit to bedownsized and thereby to be reduced in its installation space.

In the above prior art air conditioner disclosed, cooler pipes for anevaporator as a cooling heat exchanger and heater pipes for a heatercore as a heating heat exchanger are arranged at the side wall of theair conditioning unit toward the air blowing unit or at the oppositeside wall thereof. A drain port is provided at a suitable position of abottom wall part of the air conditioning unit to drain off waterdownward.

Also, in the prior art air conditioner, the cooler pipes and heaterpipes are attached to a dash panel disposed at the front of the airconditioning unit, but there is no clear description about specificpositions at which the pipes are actually attached to the dash panel.

Furthermore, in the above prior art, the bottom end of the verticallyelongated air conditioning unit is located in the vicinity of the floorof the vehicle body, whereas the air blowing unit has to be disposedsufficiently away from the floor in order to obtain legroom at the frontof the front-passenger's seat. This invites a large level differencebetween the outlet of the air blowing unit and the inlet of theair-conditioning unit. In this case, in order to smoothly send the airfrom the blowing unit to the air conditioning unit, it is necessary tospace both the units away from each other by a predetermined distance ormore in the car widthwise direction.

DISCLOSURE OF INVENTION

The present invention has been made in view of the foregoing points. Thepresent invention is directed to a vehicle air conditioner in which acooling heat exchanger and a heating heat exchanger are disposed in anair conditioning unit and air is sent from an air blowing unit disposedat the front-passenger's side of the air conditioning unit to the bottomend of the air conditioning unit, and has an object of facilitating theattachment of heater pipes and cooler pipes to a vehicle body (dashpanel) and further reducing the size of the air conditioner.

Solutions of the present invention taken to attain the above object arecharacterized in that the heater pipes and cooler pipes are arranged atthe same side of the air conditioning unit so as to be located close toeach other, and, in particular, both pipes are extended out of a sidewall of the air conditioning unit located toward the air blowing unit,brought into proximity to each other and then bent substantially at aright angle toward the dash panel.

More specifically, a first solution according to Claim 1 of theinvention is directed to a vehicle air conditioner comprising: an airconditioning unit disposed substantially in the middle of the inside ofan instrument panel in a widthwise direction of a vehicle; an airblowing unit disposed to a front-passenger's side of the airconditioning unit; an intermediate duct for ducting an air from the airblowing unit to the air conditioning unit; and a cooling heat exchangerand a heating heat exchanger disposed in the air conditioning unit, inwhich the air introduced from the intermediate duct into the airconditioning unit is allowed to pass through the cooling and heatingheat exchangers disposed in the air conditioning unit to produce aconditioned air. Further, cooler pipes connected to the cooling heatexchanger and heater pipes connected to the heating heat exchanger arearranged to extend from the same side of the air conditioning unit inthe widthwise direction of the vehicle.

With this configuration, the heater pipes and the cooler pipes arearranged at the same side of the air conditioning unit. Therefore, inattaching the air conditioning unit to the dash panel, alignment can bemade easily and workability of attachment can be increased. Since theheater pipes and the cooler pipes are arranged in proximity to eachother, this enables downsizing of the air conditioning unit.

A second solution according to Claim 2 of the invention is directed to avehicle air conditioner comprising: an air conditioning unit disposedsubstantially in the middle of the inside of an instrument panel in awidthwise direction of a vehicle; an air blowing unit disposed to afront-passenger's side of the air conditioning unit; and an intermediateduct for ducting an air from the air blowing unit to the airconditioning unit; in which the air introduced from the intermediateduct into the air conditioning unit is allowed to pass through a coolingheat exchanger and a heating heat exchanger juxtaposed one above theother in the air conditioning unit to produce a conditioned air. In thisair conditioner, cooler pipes connected to the cooling heat exchangerand heater pipes connected to the heating heat exchanger are arranged toextend from the same side of the air conditioning unit in the widthwisedirection of the vehicle.

With this configuration, like the solution according to Claim 1,workability of air conditioning unit attachment can be increased and theair conditioning unit can be made compact.

With a third solution according to Claim 3 of the invention, in thevehicle air conditioner of Claim 1 or 2, the cooler pipes and heaterpipes are extended from the same side wall of the air conditioning unit,bent substantially at a right angle, brought into proximity to eachother and then extended toward the front of the vehicle. Therefore, aspace located laterally from the side wall of the air conditioning unitcan be effectively used, and the air conditioning unit can be arrangedin proximity to the dash panel, which increases the utilization area ofthe passenger's room.

With a fourth solution according to Claim 4 of the invention, in thevehicle air conditioner of any one of Claims 1 to 3, the cooler pipesand heater pipes are extended from a side wall of the air conditioningunit, bent substantially at a right angle, brought into proximity toeach other and then extended toward the front of the vehicle, and allthe cooler and heater pipes pass through through holes in proximity toeach other in a dash panel disposed at the front of the air conditioningunit to locate distal ends thereof in an engine room beyond the dashpanel. This facilitates the attachment of the air conditioning unit tothe dash panel and improves sealing properties between all the pipes andthe dash panel.

With a fifth solution according to Claim 5 of the invention, in thevehicle air conditioner of Claim 3 or 4, the side wall of the airconditioning unit from which the cooler pipes and heater pipes areextended is at the side of the air conditioning unit located toward theair blowing unit, and the cooler pipes and heater pipes are extendedfrom between the air conditioning unit and the air blowing unit towardthe front of the vehicle. Therefore, the space between the airconditioning unit and the air blowing unit can be effectively used.Furthermore, a space located laterally from the air conditioning unitand opposite to the air blowing unit, i.e., a space on the driver's sideof the air conditioning unit, can be obtained amply. Alternatively, alarge-sized temperature-control duct can be provided on the driver'sside wall of the air conditioning unit to effectively carry out thetemperature control on the passenger's room.

With a sixth solution according to Claim 6 of the invention, in thevehicle air conditioner of any one of Claims 1 to 5, a bracket forsupporting the cooler pipes and heater pipes is formed integrally withthe air conditioning unit, and the bracket supports portions of thecooler pipes and heater pipes extending toward the front of a vehiclebody. In this manner, all the pipes are supported to a common bracket.Therefore, all the pipes can be held stably at predetermined positionsof the air conditioning unit, and the number of components can bereduced thereby providing cost reduction.

With a seventh solution according to Claim 7 of the invention, in thevehicle air conditioner of Claim 6, the heater pipes include a supplypipe for supplying a heat medium for heat application to the heatingheat exchanger, and a return pipe from the heat medium for heatapplication, the supply pipe and the return pipe are supported to thebracket so as to be arranged one above the other, and the cooler pipesare supported to the bracket below the heater pipes. Therefore, all thepipes and the bracket can be arranged compactly, and all the pipes canbe firmly supported.

With an eighth solution according to Claim 8 of the invention, in thevehicle air conditioner of Claim 6 or 7, the bracket is formed to beseparable on vertical center lines of all the cooler and heater pipes,and one separate piece of the bracket is formed integrally with the airconditioning unit, while the other separate piece is attached detachablyto said one separate piece. This facilitates attachment and detachmentof the cooler pipes and ensures alignment thereof.

With a ninth solution according to Claim 9 of the invention, in thevehicle air conditioner of any one of Claims 6 to 8, openings for coolerpipes formed in the bracket have a diameter with a predeterminedclearance left from the outer diameter of the cooler pipes, the bracketincludes a seal plate detachable with respect to the openings for coolerpipes, and the cooler pipes are fixed to the bracket by fitting the sealplate to the bracket.

Therefore, in detaching the expansion valve connected to the coolingheat exchanger and presented laterally from the side wall of the airconditioning unit, the above structure provides slight freedom ofmovement for the cooler pipes. As a result, the expansion valve can bedetached easily without removal of the bracket, which facilitatesdetachment work.

With a tenth solution according to Claim 10 of the invention, in thevehicle air conditioner of Claim 9, the seal plate has a groove for acooler pipe, the groove has a width greater than the diameter of thecooler pipe and smaller than the diameter of the opening of the bracket,and the seal plate is detachable substantially at a right angle withrespect to the cooler pipe. Therefore, the seal plate can stably securethe cooler pipe to the bracket, and detachment of the seal plate can beeasily carried out in a narrow space.

With an eleventh solution according to Claim 11 of the invention, in thevehicle air conditioner of any one of Claims 6 to 10, the bracket has aflat surface opposed to the dash panel disposed at the front of the airconditioning unit, and the flat surface is capable of being pressedagainst the peripheries of the openings for heater pipes and theopenings for cooler pipes in the dash panel. This provides improvedsealing properties between the dash panel and the pipes, and excellentwaterproof, sound insulating and heat insulating properties.Furthermore, since the dash insulators surrounding the openings can beheld by the flat surface, the dash insulators can be prevented frompeeling.

With a twelfth solution according to Claim 12 of the invention, in thevehicle air conditioner of any one of Claims 1 to 11, the cooler pipe isconnected to the cooling heat exchanger through an expansion valve, theexpansion valve is disposed adjacent the outer surface of a side wall ofthe air conditioning unit located toward the air blowing unit, anextended wall is formed integrally with the outer surface of the sidewall to cover the periphery of the expansion valve, a cover is providedto cover the extended wall, and the expansion valve is capable of beingcovered with the extended wall and the cover.

With this configuration, the extended wall and the cover prevents theexpansion valve from being exposed to the outside air without anyspecial work such as tightly wrapping the expansion valve with rubbersealing member, which significantly improves workability. Furthermore,the expansion valve can be easily attached and detached.

With a thirteenth solution according to Claim 13 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 12, the coolingheat exchanger is disposed so as to be inclined downwardly in a rear tofront direction of a vehicle body, the cooling heat exchanger isprovided with a plurality of flat tubes which are stacked in thewidthwise direction of the vehicle to extend in the lengthwise directionof the vehicle body and through which a refrigerant flows, a corrugatefin is interposed between the adjacent flat tubes, and the lower end ofthe corrugate fin is located above the lower ends of the flat tubes.

With this configuration, condensate produced in the cooling heatexchanger can easily flow along the lower ends of the flat tubes in arear to front direction of the vehicle body. Therefore, the condensatecan be promptly recovered from the cooling heat exchanger, whichsignificantly reduces that the condensate is transferred above thecooling heat exchanger.

With a fourteenth solution according to Claim 14 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 13, a drain portis provided in a bottom wall part of the air conditioning unit, and thedrain port is disposed at the same side of the air conditioning unit atwhich the cooler pipes and the heater pipes are arranged, in proximityto the cooler pipes and the heater pipes, and toward the front of thevehicle body. Therefore, the drain pipe can be arranged collectivelywith the heater and cooler pipes, which provides their compact layout.Furthermore, since the drain pipe and the heater and cooler pipes can beattached together to the dash panel, this improves workability ofassembly and sealing properties between the pipes and the dash panel.

With a fifteenth solution according to Claim 15 of the invention, in thevehicle air conditioner of Claim 14, a drain passage continuous with thedrain port is provided, and the exit of the drain passage is extended,together with the cooler pipes and the heater pipes, from the side wallof the air conditioning unit located toward the air blowing unit. Thisenables effective use of a space between the air conditioning unit andthe air blowing unit, and provides utilization of the opposite side wallof the air conditioning unit and extension of a space on the driver'sseat side of the air conditioning unit.

With a sixteenth solution according to Claim 16 of the invention, in thevehicle air conditioner of Claim 15, a drain pipe is connected to theexit of the drain passage, and the drain pipe is disposed toward thefront of the vehicle body. Therefore, the drain pipe, the heater pipesand the cooler pipes can be arranged collectively in the same directiontoward the dash panel. This provides compact piping layout andsignificantly improves workability of attachment of the pipes to thedash panel.

With a seventeenth solution according to Claim 17 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 16, the heatingheat exchanger and the cooling heat exchanger are arranged substantiallyhorizontally in the air conditioning unit with the heating heatexchanger located above the cooling heat exchanger, the cooling heatexchanger is inclined downwardly in a rear to front direction of thevehicle body, a lower space into which an air from the intermediate ductis introduced is provided under the cooling heat exchanger, a bottomwall part of the air conditioning unit is provided under the lowerspace, a drain port is formed in the bottom wall part integrally withthe air conditioning unit, and a drain passage continuous with the drainport is extended from the side wall part of the air conditioning unitand disposed closer to the front of the vehicle body than theintermediate duct.

Therefore, the drain passage and the cooler pipes can be disposedbetween the air conditioning unit and the air blowing unit withoutinterfering with the intermediate duct. In another aspect, theintermediate duct can be arranged to send an air from the air blowingunit to the air conditioning unit effectively without being affected bythe drain passage and the cooler pipes.

With an eighteenth solution according to Claim 18 of the invention, inthe vehicle air conditioner of Claim 16 or 17, the heater pipes and thecooler pipes are supported one above another to the bracket, and thedrain pipe is disposed below the cooler pipes. Therefore, the heater andcooler pipes can be disposed in a compact and collective arrangement.

With a nineteenth solution according to Claim 19 of the invention, inthe vehicle air conditioner of any one of Claims 15 to 18, an attachmentpart through which the air conditioning unit is attached to a dash paneldisposed at the front of the air conditioning unit is providedintegrally with the drain passage in proximity to the exit of the drainpassage. This increases the rigidity of surroundings of the drainpassage, and enables the drain passage to be attached stably at apredetermined position of the dash panel thereby increasing theprecision of assembly.

With a twentieth solution according to Claim 20 of the invention, in thevehicle air conditioner of any one of Claims 13 to 19, a bottom wallpart of the air conditioning unit has an inclined surface that is lowestin level at the drain port, is highest in level at the corner diagonallyopposite to the drain port and is thus gradually downwardly inclinedfrom the diagonally opposite corner toward the drain port. Therefore,condensate in the air conditioning unit can be smoothly guided to thedrain port.

With a twenty-first solution according to Claim 21 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 20, theintermediate duct has an inclined duct connected to the air blowing unitand inclined obliquely downwardly from the air blowing unit toward theair conditioning unit, and a horizontal duct connected with the inclinedduct and the air conditioning unit to form a substantially horizontalair passage.

With this configuration, an air flowing through the intermediate duct issmoothly changed in direction from an obliquely downward flow to anapproximate horizontal flow and then introduced into the airconditioning unit. Therefore, the air flow colliding with the bottomwall part is significantly reduced, resulting in providing an excellentfunction of preventing condensate in the bottom wall part from beinginvolved into the air flow.

With a twenty-second solution according to Claim 22 of the invention, inthe vehicle air conditioner of Claim 21, the bottom wall part of the airconditioning unit has an inclined surface that is lowest in level at thedrain port, is highest in level at the corner diagonally opposite to thedrain port and is thus gradually downwardly inclined from the diagonallyopposite corner toward the drain port, the middle of the bottom wallpart is provided with a flat surface portion, and the drain passage isalso inclined downwardly from the drain port toward the exit of thedrain passage. Therefore, an air introduced into the air conditioningunit is better separated from condensate guided to the drain port,resulting in a prompt discharge of the condensate and a smooth air flow.

With a twenty-third solution according to Claim 23 of the invention, inthe vehicle air conditioner of any one of Claims 13 to 22, a rib isprovided in a standing manner on the bottom wall part of the airconditioning unit and along the flowing direction of the air introducedthrough the intermediate duct, and the drain port is provided in aportion of the bottom wall part closer to the front of the vehicle bodythan the rib.

With this configuration, the rate of air flow sent from the intermediateduct to the air conditioning unit is smaller in the portion of thebottom wall part closer to the front of the vehicle body than the rib.Therefore, condensate can be effectively prevented from being taken intothe cooling heat exchanger located above by the air flow.

With a twenty-fourth solution according to Claim 24 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 23, the heatingheat exchanger and the cooling heat exchanger are arranged substantiallyhorizontally in the air conditioning unit with the heating heatexchanger located above the cooling heat exchanger, the cooling heatexchanger is inclined downwardly in a rear to front direction of thevehicle body, a lower space into which an air from the intermediate ductis introduced is provided under the cooling heat exchanger, a bottomwall part of the air conditioning unit is provided under the lowerspace, the cooling heat exchanger is inclined downwardly in a rear tofront direction of the vehicle body, the intermediate duct has anapproximately triangular section at a connected portion with the lowerspace, the intermediate duct has an inclined duct inclined obliquelydownwardly from the air blowing unit toward the air conditioning unit,and a horizontal duct connected from the inclined duct to the airconditioning unit to form a substantially horizontal air passage, theinclined duct has an approximately rectangular section at a connectedportion with the air blowing unit, and the inclined duct has anapproximately triangular section at a connected portion with thehorizontal duct.

With this configuration, air smoothly flows through the intermediateduct, a partial air flowing through one side of the horizontal ducthaving a larger sectional area, i.e., a portion thereof located towardthe rear of the vehicle body, is introduced at high speed into the airconditioning unit, and a partial air flowing through the other side ofthe horizontal duct is introduced at low speed into the air conditioningunit. Therefore, the high-speed air flow inside of the air conditioningunit is smoothly introduced to the cooling heat exchanger, resulting inimproved heat exchanger effectiveness.

With a twenty-fifth solution according to Claim 25 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 24, the airconditioning unit is provided with a temperature control damper forcontrolling the temperature of a conditioned air by changing the ratioof the flow rate of air passing through the heating heat exchanger tothe flow rate of air introduced into the air conditioning unit, and ablow-out direction switching damper for changing the blow-out directionof the conditioned air, and drive mechanisms and actuators for drivingthe temperature control damper and the blow-out direction switchingdamper, respectively, are disposed on the side wall of the airconditioning unit located toward the air blowing unit.

With this configuration, an air from the air blowing unit smoothly flowsthrough the intermediate duct, is introduced into the lower space of theair conditioning unit, is turned upward, and then passes through thecooling and heating heat exchangers. During the time, the temperaturecontrol damper is driven by the actuator via the drive mechanism, thetemperature of the conditioned air is controlled by changing the ratioof the flow rate of air passing through the heating heat exchanger tothe flow rate of air introduced into the air conditioning unit. Theconditioned air produced in this manner is changed in blow-out directionby the blow-out direction switching damper, and then supplied to adesired place in the passenger's room.

In this case, the drive mechanisms and actuators for the two dampers aredisposed on the side wall of the air conditioning unit located towardthe air blowing unit, and collected in a dead space between the airblowing unit and the air conditioning unit which are spaced apart fromeach other by a distance between both ends of the intermediate duct.This makes the air conditioner more compact and reduces its installationspace. Furthermore, collective arrangement of the two actuatorsdecreases the number of processes for assembly of the air conditioningunit and the number of processes for attachment thereof to the vehiclebody.

With a twenty-sixth solution according to Claim 26 of the invention, inthe vehicle air conditioner of Claim 25, the temperature control damperis formed of two damper members, and control of swing motions of the twodamper members allows the ratio of the flow rate of air passing throughthe heating heat exchanger to be changed thereby controlling thetemperature of the conditioned air.

In general, to increase the area of the air passage for introduction ofair into the heating heat exchanger or bypassing of the heating heatexchanger, it is required to provide a large-area temperature controldamper for swing motion. This involves increasing the distance betweenthe cooling and heating heat exchangers, resulting in increased heightof the air conditioning unit. Unlike this, in this invention, thetemperature control damper between the cooling and heating heatexchangers is formed of two damper members. Therefore, the area of theair passage for introduction of air into the heating heat exchanger orbypassing of the heating heat exchanger can be increased without thespace between both the heat exchangers being increased.

With a twenty-seventh solution according to Claim 27 of the invention,in the vehicle air conditioner of Claim 26, the two damper members arecontrolled to differ from each other in their opening/closing timings atwhich air passages toward the heating heat exchanger are opened or shutoff. This provides precise temperature control.

With a twenty-eighth solution according to Claim 28 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 27, the airblowing unit is provided with an inside/outside air switching damper forcontrolling the amount of air taken in from the outside of a passenger'sroom and the amount of air taken in from the inside of the passenger'sroom, and an actuator for driving the inside/outside air switchingdamper is disposed on a side wall of the air blowing unit located towardthe air conditioning unit.

Thus, the actuator for the inside/outside air switching damper isdisposed on the side wall of the air blowing unit located toward the airconditioning unit, i.e., in a dead space between both the units, likethe drive mechanisms and actuators for the air conditioning unit. Thisfurther reduces the size of the air conditioner, the number of processesfor assembly of the units and the number of processes for attachment ofthe units to the vehicle body.

With a twenty-ninth solution according to Claim 29 of the invention, inthe vehicle air conditioner of any one of Claims 1 to 28, the airconditioning unit is divided into upper and lower casings and the uppercasing is divided into right and left parts, and the cooling heatexchanger and the heating heat exchanger are held sandwiched between thetwo divided parts of the upper casing.

With this configuration, the cooling and heating heat exchangers can beeasily assembled and securely held. Furthermore, since no verticallyseparated surface is formed in the lower casing, this eliminates fear ofleakage of condensate and provides ensured discharge of condensatethrough the drain port.

With a thirtieth solution according to Claim 30 of the invention, in thevehicle air conditioner of Claim 29, a dash panel forming a partitionfor separating the air conditioning unit from an engine room is providedat the side of the air conditioning unit located toward the front of thevehicle body, and the drain port is provided in a portion of the lowercasing located toward the air blowing unit and toward the front of thevehicle body, the drain passage is extended from the drain port towardthe air blowing unit substantially in parallel with the dash panel toprotrude from the air conditioning unit, a drain pipe is connected tothe exit of the drain passage, the drain pipe is extended in a directionorthogonal to the dash panel and inserted into an opening in the dashpanel, and the drain passage is formed of an elongated-groove partformed integrally with the lower casing, and a cover for the elongatedgroove part formed integrally with the upper casing.

With this configuration, the drain passage is formed not as a hollowbody but as an elongated groove part in the lower casing, and a separatemember covers the upper surface of the groove part. This enablesintegral formation of the drain passage with the lower casing and easyformation thereof even if the depth and length of the elongated grooveare rather large, provides flexibility to the shape and size of thedrain passage, ensures a space for storing condensate, and provides aconfiguration of the space that can discharge condensate smoothly.

A thirty-first solution according to Claim 31 of the invention isdirected to a vehicle air conditioner comprising: an air conditioningunit disposed substantially in the middle of the inside of an instrumentpanel in a widthwise direction of a vehicle; an air blowingunit-disposed to a front-passenger's side of the air conditioning unit;an intermediate duct for ducting an air from the air blowing unit to theair conditioning unit; and a cooling heat exchanger and a heating heatexchanger disposed in the air conditioning unit, in which the airintroduced from the intermediate duct into the air conditioning unit isallowed to pass through the cooling and heating heat exchangers disposedin the air conditioning unit to produce a conditioned air. Further, adrain port is provided in a bottom wall part of the air conditioningunit, the drain port is disposed in a portion of the bottom wall partlocated toward the front of the vehicle body and along a side wall ofthe air conditioning unit, and cooler pipes for the cooling heatexchanger are arranged along the same side wall that the drain port islocated.

With this configuration, the drain port and the cooler pipes aredisposed at the same side of the air conditioning unit. This facilitatesthe alignment and attachment work in attaching the air conditioning unitto the dash panel. Since the drain pipe connected to the drain port andthe cooler pipes are arranged in proximity to each other, this makes theair conditioning unit more compact.

A thirty-second solution according to Claim 32 of the invention isdirected to a vehicle air conditioner comprising: an air conditioningunit disposed substantially in the middle of the inside of an instrumentpanel in a widthwise direction of a vehicle; an air blowing unitdisposed to a front-passenger's side of the air conditioning unit; anintermediate duct for ducting an air from the air blowing unit to theair conditioning unit; and a cooling heat exchanger and a heating heatexchanger disposed in the air conditioning unit, in which the airintroduced from the intermediate duct into the air conditioning unit isallowed to pass through the cooling and heating heat exchangers disposedin the air conditioning unit to produce a conditioned air. Further, adrain port is provided in a bottom wall part of the air conditioningunit, a drain passage connected integrally with the drain port isdisposed to extend laterally of the air conditioning unit, a drain pipeis connected to the exit of the drain passage, and the drain pipe isdisposed to extend into an engine room.

With this configuration, the drain passage is disposed to extendlaterally from the projecting plane of the air conditioning unit asviewed in a vertical direction, and the drain pipe is connected to theexit of the drain passage. Therefore, there is no need for alignment ofthe opening of the dash panel and the drain port in a front to reardirection of the vehicle body, and their positional relationship can beset freely by changing the length of the drain passage, which providesgreat design flexibility.

Furthermore, since the drain passage can form a space for storingcondensate, this reduces the amount of condensate stored in the bottomwall part and substantially eliminates involvement of condensate intothe air flow being introduced into the cooling heat exchanger.

A thirty-third solution according to Claim 33 of the invention isdirected to a vehicle air conditioner comprising: an air conditioningunit disposed substantially in the middle of the inside of an instrumentpanel in a widthwise direction of a vehicle; an air blowing unitdisposed to a front-passenger's side of the air conditioning unit; andan intermediate duct for ducting an air from the air blowing unit to theair conditioning unit, in which the air introduced from the intermediateduct into the air conditioning unit is allowed to pass through a coolingheat exchanger and a heating heat exchanger juxtaposed one above theother in the air conditioning unit to produce a conditioned air.Further, a drain port is provided in a bottom wall part of the airconditioning unit, the drain port is disposed in a portion of the bottomwall part located toward the front of the vehicle body and along a sidewall of the air conditioning unit, and cooler pipes for the cooling heatexchanger are arranged along the same side wall that the drain port islocated.

With this configuration, like the solution according to Claim 31, theair conditioning unit can be easily attached to the dash panel and canbe made more compact.

A thirty-fourth solution according to Claim 34 of the invention isdirected to a vehicle air conditioner comprising: an air conditioningunit disposed substantially in the middle of the inside of an instrumentpanel in a widthwise direction of a vehicle; an air blowing unitdisposed to a front-passenger's side of the air conditioning unit; andan intermediate duct for ducting an air from the air blowing unit to theair conditioning unit, in which the air introduced from the intermediateduct into the air conditioning unit is allowed to pass through a coolingheat exchanger and a heating heat exchanger juxtaposed one above theother in the air conditioning unit to produce a conditioned air.Further, a drain port is provided in a bottom wall part of the airconditioning unit, a drain passage connected integrally with the drainport is disposed to extend laterally of the air conditioning unit, adrain pipe is connected to the exit of the drain passage, and the drainpipe is disposed to extend into an engine room.

This configuration, like the solution according to Claim 32, providessignificantly improved design flexibility to the drain port and theopening of the dash panel, and enables condensate to be stored in thedrain passage to prevent roll-up of condensate.

With a thirty-fifth solution according to Claim 35 of the invention, inthe vehicle air conditioner of any one of Claims 31 to 34, the side wallof the air conditioning unit at which the drain passage is disposed isat the side of the air conditioning unit located toward the air blowingunit. Therefore, the space between the air conditioning unit and the airblowing unit can be effectively used. Furthermore, a space locatedlaterally from the air conditioning unit and opposite to the air blowingunit, i.e., a space on the driver's side of the air conditioning unit,can be obtained amply. Alternatively, a large-sized temperature-controlduct can be provided on the driver's side wall of the air conditioningunit to effectively carry out the temperature control on the passenger'sroom.

With a thirty-sixth solution according to Claim 36 of the invention, inthe vehicle air conditioner of any one of Claims 31 to 34, a bracket forsupporting the cooler pipes is formed integrally with the airconditioning unit, and portions of the cooler pipes connected to thecooling heat exchanger, extended from the side wall of the airconditioner, bent substantially at a right angle and extended toward thefront of the vehicle body are attached to the bracket. Therefore, thecooler pipes can be held stably at predetermined positions of the airconditioning unit.

With a thirty-seventh solution according to Claim 37 of the invention,in the vehicle air conditioner of Claim 36, the bracket is formed to beseparated on vertical lines passing through the middles of the coolerpipes in their radial direction, and one separate piece of the bracketis formed integrally with the air conditioning unit, while the otherseparate piece is attached detachably to said one separate piece. Thisfacilitates attachment and detachment of the cooler pipes and ensuresalignment thereof.

With a thirty-eighth solution according to Claim 38 of the invention, inthe vehicle air conditioner of Claim 36, openings for cooler pipesformed in the bracket have a diameter with a predetermined clearanceleft from the outer diameter of the cooler pipes, and the cooler pipesare fixed to the bracket by fitting a seal plate to the bracket, theseal plate being disposed detachably from the bracket. Therefore, indetaching the expansion valve connected to the cooling heat exchangerand presented laterally from the side wall of the air conditioning unit,the above structure provides slight freedom of movement for the coolerpipes. As a result, the expansion valve can be detached easily withoutremoval of the bracket, which facilitates detachment work.

With a thirty-ninth solution according to Claim 39 of the invention, inthe vehicle air conditioner of Claim 37, openings for cooler pipesformed in the bracket have a diameter with a predetermined clearanceleft from the outer diameter of the cooler pipes, and the cooler pipesare fixed to the bracket by fitting a seal plate to the bracket, theseal plate being disposed detachably from the bracket. Therefore, thesame effects as in the solution according to Claim 38 can be obtained.

With a fortieth solution according to Claim 40 of the invention, in thevehicle air conditioner of Claim 38, the seal plate has a groovecorresponding to a cooler pipe, the groove has a width greater than thediameter of the cooler pipe and smaller than the diameter of the openingof the bracket, and the seal plate is detachable substantially at aright angle with respect to the cooler pipe. Therefore, the seal platecan stably secure the cooler pipe to the bracket.

With a forty-first solution according to Claim 41 of the invention, inthe vehicle air conditioner of Claim 39, the seal plate has a groovecorresponding to a cooler pipe, the groove has a width greater than thediameter of the cooler pipe and smaller than the diameter of the openingof the bracket, and the seal plate is detachable substantially at aright angle with respect to the cooler pipe. Therefore, the same effectas in the solution according to Claim 40 can be obtained.

With a forty-second solution according to Claim 42 of the invention, inthe vehicle air conditioner of any one of Claims 31 to 34, the drainport is disposed in a portion of the bottom wall part of the airconditioning unit located toward the front-passenger's seat and towardthe front of the vehicle body, and the drain passage is disposed at theside wall of the air conditioning unit located toward thefront-passenger's seat to extend from the air conditioning unit. In thismanner, the drain port is open at a position that is not susceptible tothe air flow sent from the intermediate duct to the air conditioningunit, and condensate is guided to the drain passage which is outside ofthe projecting plane of the air conditioning unit. This preventscondensate from being involved into the cooling heat exchanger.

With a forty-third solution according to Claim 43 of the invention, inthe vehicle air conditioner of Claim 42, the bottom wall part of the airconditioning unit has an inclined surface that is lowest in level at thedrain port, is highest in level at the corner diagonally opposite to thedrain port and is thus gradually downwardly inclined from the diagonallyopposite corner toward the drain port, and the drain passage is alsoinclined downwardly from the drain port toward the exit of the drainpassage. Therefore, condensate can be promptly collected to the drainport and guided to the exit of the drain passage.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view in appearance of an air conditioneraccording to an embodiment of the present invention as seen from theleft rear.

FIG. 2 is a perspective view in appearance of the air conditioner asseen from the right rear.

FIG. 3 is a rear view in appearance of the air conditioner.

FIG. 4 is an illustration of how the air conditioner is disposed in avehicle.

FIG. 5 schematically illustrates the structure of the air conditionerand corresponds to FIG. 3.

FIG. 6 is a sectional view of an air conditioning unit showing itsinternal structure.

FIG. 7 is an illustration of how an evaporator is disposed.

FIG. 8 shows sectional configurations of flat tubes and corrugate finsin the evaporator of FIG. 7.

FIG. 9 is a front view in appearance of the air conditioning unit.

FIG. 10 illustrates how heater pipes and cooler pipes are attached tothe air conditioning unit.

FIG. 11 is a view of the attachment of the heater and cooler pipes ofFIG. 8 as seen from the opposite direction.

FIG. 12 is a view of the air conditioner as seen from the air blowingunit side, wherein the air conditioning unit is attached to a dashpanel.

FIG. 13 is a perspective view of a bottom wall part of the airconditioning unit as seen from the left rear.

FIG. 14 is a perspective view of the bottom wall part of the airconditioning unit as seen from the right front.

FIG. 15 is a plan view of the bottom wall part of the air conditioningunit.

FIG. 16 is a front view of the bottom wall part of the air conditioningunit.

FIG. 17 is a side view of the bottom wall part of the air conditioningunit.

FIG. 18 is a perspective view of an intermediate duct.

FIG. 19 is a perspective view of an air conditioner for a left-handdrive car.

FIG. 20 is a perspective view of an air conditioning unit of the airconditioner of FIG. 19.

FIG. 21 is a partly enlarged view of a bracket of the air conditioningunit of FIG. 20 and illustrates how the heater pipes and cooler pipesare attached to the bracket.

FIG. 22 is a view of the bracket of FIG. 21 seen from the oppositedirection.

FIG. 23 is a view of the air conditioning unit of the air conditioner ofFIG. 19 as seen from the engine room side.

FIG. 24 illustrates how an expansion valve box is attached to a casing.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described belowwith reference to the drawings.

FIGS. 1 to 3 shows the appearance of an air conditioner 1 according to apreferred embodiment of the present invention. This air conditioner 1 ishoused inside of an instrument panel 2 disposed in a passenger's room ofa car, as shown in FIG. 4. This car is a so-called right-hand drive carin which a driver's seat and a front passenger's seat are located at theright and left sides of the vehicle body, respectively. A dash panel P(as shown in FIGS. 6 and 10) separates an engine room located at thefront of the vehicle body from the front side of the passenger's room.It should be noted herein that the vehicle body front and vehicle bodyrear of the air conditioner 1 are referred to as the front and rear ofthe air conditioner 1.

As shown in FIG. 3, the air conditioner 1 essentially consists of an airblowing unit 3, an air conditioning unit 4 for cooling an air from theair blowing unit 3, controlling the temperature of the air and thensupplying the air to the passenger's room, and an intermediate duct 5through which the air from the blowing unit 3 is sent to the airconditioning unit 4. The air conditioning unit 4 is disposedsubstantially in the widthwise middle of the car, while the air blowingunit 3 is disposed a predetermined distance leftward away from the airconditioning unit 4 and to the front of the front passenger's seat. Thebottom end of the air blowing unit 3 is located at an upper level thanthe bottom end of the air conditioning unit 4 to ensure an amplerlegroom for the front-seat passenger.

The air blowing unit 3 includes a casing 6 divided into right and leftparts substantially at the car widthwise middle, and the two parts areintegrated into a single piece using a fastener or the like. The upperportion of the casing 6 includes an air intake part 7 for taking an airinto the air conditioner 1. The lower portion of the casing 6 includesan air blowing part 8 for sending the intake air to the air conditioningunit 4. The upper portion of the air intake part 7 is formed with anoutside air intake 10 through which an air outside of the passenger'sroom is taken in via a duct (not shown), and an inside air intake 11through which an air inside of the passenger's room is taken in.Further, inside of the air intake part 7, an inside/outside airswitching damper 12 is provided to make one of the inside and outsideair intakes 10 and 11 open and the other closed.

More specifically, the upper portion of the air intake part 7 has afront wall of rectangular shape that inclines toward the rear of thevehicle body in proceeding to the top and a rear wall of rectangularshape that inclines toward the front of the vehicle body in proceedingto the top. The front and rear walls are continuous at their upper edgesso that the upper portion of the air intake part 7 has an approximatelytriangular section when viewed in the car widthwise direction. The frontand rear walls have the outside and inside air intakes 10 and 11 openedin rectangular shape, respectively. Each air intake is formed integrallywith a grille 13. The side walls of the air intake part 7 connect thecorresponding side edges of the front and rear walls. The inside/outsideair switching damper 12 is of rectangular shape larger than each of theair intakes 10 and 11, and has a shaft that is located at its upper edgeand extends in the car widthwise direction. Both ends of the shaft aresupported to the upper ends of the pair of side walls of the air intakepart 7.

The lower end of the inside/outside air switching damper 12 is providedwith a connecting part (not shown) passing through one of the side wallsof the air intake part 7 so as to be connected with an output shaft ofan actuator 15 attached to that side wall of the air intake part 7. Thisside wall is formed integrally with a boss to which the actuator 15 isfastened with screws. The actuator 15 operates in response to a signalfrom an air conditioning controller (not shown) disposed in the vehiclebody. A signal line from the air conditioning controller is connectedwith a coupler 17 for the actuator 15.

When the actuator 15 angularly moves the inside/outside air switchingdamper 12 about the shaft to the position that the outside air intake 10is fully open, the inside air intake 11 is fully closed. Thus, the airblowing unit 3 enters an outside air intake mode in which only anoutside air is taken in the unit. On the other hand, when the actuator15 angularly moves the inside/outside air switching damper 12 oppositelyfrom that position to the position that the outside air intake 10 isfully closed, the inside air intake 11 is fully open. Thus, the airblowing unit 3 enters an inside air circulation mode.

As shown in FIG. 5, the lower portion of the air intake part 7 isprovided with a filter accommodation part 21 for accommodating a filter20 for filtering the intake air. Although not shown, an opening isformed in a portion of the casing 6 located to the rear side of thefilter accommodation part 21, which enables the filter 20 to be replacedwith new one through the opening. The air blowing part 8 is locatedunder the filter accommodation part 21. In the air blowing part 8, acentrifugal multi-blade fan is placed as an air blowing fan 23 to extendits rotating shaft vertically, and a fan-driving motor 24 is disposedbelow the air blowing fan 23. As shown in the arrows in FIG. 5, therotation of the air blowing fan 23 causes air to be taken in from abovethe air intake part 7, to pass through the filter 20 and to beintroduced into the air blowing part 8.

The right wall of the air blowing part 8 is formed with an opening 8 aand is connected at the opening 8 a to the left end of the intermediateduct 5. The air blowing and air conditioning units 3 and 4 are locatedaway from each other by a distance between both ends of the intermediateduct 5. As shown in the arrow in FIG. 5, the air from the air blowingunit 3 is smoothly sent into the air conditioning unit 4 by passingthrough the intermediate duct 5.

As shown in FIG. 5 again, the intermediate duct 5 has an inclined duct 5a and a horizontal duct 5 b. The inclined duct 5 a is formed toobliquely downwardly extend from the left end of the intermediate duct 5toward the bottom end of the air conditioning unit 4. The horizontalduct 5 b is communicated at its right end with the inside of the airconditioning unit 4 through an opening 25 formed at the bottom end sideof a casing 30 for the air conditioning unit 4.

As shown in FIG. 18, the inclined duct 5 a is formed to have anapproximately rectangular section at its left end and an approximatelytriangular section at its right end and smoothly change itscross-sectional shape from rectangle to triangle thereby reducing airturbulence and air resistance. The horizontal duct 5 b continues to havean approximately triangular section and is internally provided with aplurality of projections to straighten the air flow. The horizontal duct5 b and the opening 25 of the casing 30 are connected at their similartriangular sections with each other.

In particular, a high-speed air in the radially outer side (the vehiclebody rear side) of the air blowing unit 3 is sent to a wider area side(the vehicle body rear side) of the opening 25 of substantiallytriangular shape, while a low-speed air in the radially inner side (thevehicle body front side) of the air blowing unit 3 is sent to a narrowerarea side (the vehicle body front side) of the opening 25 ofsubstantially triangular shape.

As shown in FIG. 2, the intermediate duct 5 is provided at its top wallwith a control circuit 26 for changing the rpm of the fan-driving motor24. The control circuit 26 is provided at its top with a coupler 27 towhich a connector from the air conditioning controller is connected.

The air conditioning unit 4 has the casing 30 which is generallyvertically elongated and formed in a rectangular box of larger size thanthat of the casing 6 for the air blowing unit 3. The casing 30 isdivided into a bottom wall part 31 and a body part 32 one above theother; the bottom wall part 31 forms a lower casing and the body part 32forms an upper casing. Further, the body part 32 is divided into twoportions substantially at the middle in the widthwise direction of thecar, like the air blowing unit 3.

As shown in FIG. 6, inside of the casing 30, an evaporator 33 as anelement of a refrigeration cycle is placed above the opening 25 at whichthe casing 30 is connected to the intermediate duct 5, and a heater core34 is placed above the evaporator 33. The upper portion of the casing 30is formed with a plurality of air outlets for a conditioned air. Asshown in the arrows in FIG. 5, the air flow from the air blowing unit 3turns an upward flow in the air conditioning unit 4.

The evaporator 33 is a cooling heat exchanger for cooling the air fromthe air blowing unit 3. The evaporator 33 is formed by stacking multipleflat tubes 33 a, each made of a thin metal plate such as an aluminumplate, in parallel and interposing a corrugate fin 33 b made of a thinmetal plate between the adjacent flat tubes 33 a. As shown in FIGS. 7and 8, the flat tube 33 a is a hollow body formed by superposing halvedcontainers one on another in opposed relation to extend in a rear tofront direction of the vehicle body. The corrugate fin 33 b interposedbetween the flat tubes 33 a is formed to have a wave shape when viewedfrom above. The bottom end of the corrugate tube 33 b is located abovethe bottom ends of the adjacent flat tubes 33 a. In other words, thebottom ends of the flat tubes 33 a are located below the bottom ends ofthe corrugate fins 33 b. Therefore, a space between the bottom ends ofthe adjacent flat tubes 33 a functions as a space for guiding condensatefalling from the corrugate fin 33 b down to the bottom end surface ofthe flat tube 33 a in a rear to front direction of the vehicle body.

The flat tubes 33 a of the evaporator 33 are constructed so that alow-temperature refrigerant produced by refrigeration cycle circulatestherein to cool the air passing upwardly through the evaporator 33.Specifically, although not shown, tanks are provided at both sides ofthe evaporator 33 adjacent to both ends of all the flat tubes 33 a tocommunicate with the tubes. One of the tanks is divided into an inflowtank section and an outflow tank section by a partition plate disposedat the middle thereof in a stacking direction of the flat tubes 33 a.The refrigerant flowing into the inflow tank section flows into theother tank through upstream tubes connected to the inflow tank section,and then flows into the outflow tank section of said one tank throughdownstream tubes.

The evaporator 33 is placed to extend the tubes in the car lengthwisedirection and to locate portion thereof closer to the rear of the car athigher level, thereby passing all the air from the air blowing unit 3through the evaporator 33. The inflow and outflow tank sections of theevaporator 33 are connected with corresponding cooler pipes 90. Eachcooler pipe 90 is provided so as to be extended outwardly from a leftside wall 30 a (shown in FIG. 5) of the casing 30 for the airconditioning unit 4, bent substantially at a right angle and thenextended toward the front of the vehicle body.

The heater core 34 is horizontally placed above the evaporator 33 toapply heat to the air from the evaporator 33. The heater core 34 isconnected with heater pipes 91 including introduction and dischargepipes for a high-temperature engine cooling water. Each heater pipe 91is provided so as to be extended outwardly from the left side wall 30 a(shown in FIG. 5) of the casing 30 for the air conditioning unit 4, bentsubstantially at a right angle, and then extended toward the front ofthe vehicle body. The heater pipes 91 and cooler pipes 90 are supportedto the air conditioning unit 4 by a bracket 92.

Next, description will be made about the bracket 92 and its surroundingswith reference to FIGS. 9 to 12. The heater pipes 91 are juxtaposed oneabove the other. One of the cooler pipes 90 is arranged immediatelybelow the heater pipe 91, while the other is arranged below said onecooler pipe 90 and slightly off to the side. The bracket 92 includes afixed bracket 92 a integrally formed with the casing 30 in the airconditioning unit 4 and a detachable bracket 92 b. The vertical planethat divides the bracket 92 into the fixed and detachable brackets 92 aand 92 b runs through the vertical center lines of the heater tubes 91and the cooler tubes 90.

The fixed and detachable brackets 92 a and 92 b of the bracket 92 haverecesses corresponding to arcs obtained by halving the heater pipes 91and cooler pipes 90, and the recesses form openings 94 and 95 for theheater pipes 91 and cooler pipes 90 when both the brackets 92 a and 92 bare abutted on each other. The diameter of the opening 94 for the heaterpipe 91 is substantially equal to the outer diameter of the heater pipe91. Therefore, when the detachable bracket 92 b is attached to the fixedbracket 92 a, the heater pipes 91 can be fixed in the openings 94.

On the other hand, the opening 95 for the cooler pipe 90 is formed witha predetermined clearance left from the outer diameter of the coolerpipe 90. In this manner, when the detachable bracket 92 b is attached tothe fixed bracket 92 a, the cooler pipes 90 can be moved slightly.Therefore, at the attachment and detachment of an expansion valve box 96for the evaporator 33 to and from the left side wall 30 a of the casing30, the expansion valve box 96 can be attached and detached, withoutremoval of the evaporator 33 from the casing 30, by slightly moving thecooler pipe 90.

To support the cooler pipes 90 to the bracket 92, seal plates 93 areprovided. Each seal plate 93 has a half-round recess 97 of correspondingdiameter to the outer diameter of the cooler pipe 90, and is laterallyslidable by being guided in an elongated groove provided in thedetachable bracket 92 b. The cooler pipe 90 can be fixed to the bracket92 by inserting the corresponding seal plate 93 to a predeterminedposition of the detachable bracket 92 b. When the seal plate 93 isinserted in the groove to the predetermined position, a lug 98 on aplate 99 integrally formed with the seal plate 93 is fitted into arecess (not shown) of the detachable bracket 92 b. On the other hand, inslidingly pulling the seal plate 93 out of the groove, the plate 99 needonly be pinched to disengage the lug 98 from the recess and in thisstate, slid out of the groove. Thus, the seal plate 93 can be easilyinserted into and pulled out of the groove.

It will be understood that the detachable bracket 92 b can be attachedto the fixed bracket 92 a by screw fixation B in the same direction aswith its assembly.

In this embodiment, the seal plates 93 are provided individually for thecooler pipes 90. However, a single seal plate may be provided for boththe cooler pipes 90. Further, seal plates may also be provided for theheater pipes 91 and a drain pipe 83 to fix them.

Next, description will be made about a structure for dischargingcondensate in the air conditioning unit 4. Condensate produced in theevaporator 33 during air cooling is discharged outside through a drain35 provided in the bottom wall part 31 of the casing 30. As shown inFIGS. 13 to 17, the drain 35 includes a drain port 80 and a drainpassage 81 formed at the front-end left corner (the air blowing unitside) of the bottom wall part 31. The drain port 80 is formed integrallywith the bottom wall part 31, and the drain passage 81 is formedintegrally with the drain port 80. The drain passage 81 extends from thedrain port 80 toward the air blowing unit substantially in parallel withthe dash panel. The exit 82 of the drain passage 81 extends beyond theleft side wall 30 a of the casing 30 in the air conditioning unit 4leftward (toward the air blowing unit). The exit 82 is connected withthe drain pipe 83 substantially at a right angle. The end of the drainpipe 83 is inserted into a through hole 102 in the dash panel P.

The bottom wall part 31 has an inclined surface that is lowest in levelat the drain port 80, is highest in level at the corner diagonallyopposite to the drain port 80 and is thus gradually downwardly inclinedfrom the diagonally opposite corner toward the drain port 80. The drainpassage 81 is also inclined downwardly from the drain port 80 toward theexit 82. Such a configuration guides condensate stored in the bottomwall part 31 to flow toward the drain port 80, then flow toward the exit82 through the drain passage 81, and then flow out of the passenger'sroom through the drain pipe 83.

Particularly, the inclined surface of the bottom wall part 31 of thecasing 30 is branched into two and then merged at the left end of thebottom wall part 31 so that the left end is located at a lower levelwith respect to the right end of the horizontal duct 5 b. With thisconfiguration, even if a moving vehicle tilts on the front passenger'sside, condensate stored in the bottom wall part 31 can be prevented fromflowing back to the air blowing unit through the intermediated duct 5.

The intermediate duct 5 is connected with the air blowing unit 3 and, asshown in FIG. 5, has an inclined duct 5 a and a horizontal duct 5 b. Theinclined duct 5 a is inclined obliquely downward from the air blowingunit 3 toward the air conditioning unit 4. The horizontal duct 5 bcommunicates the inclined duct 5 a with the casing 30 of the airconditioning unit 4. The inclined duct 5 a is formed separately from thehorizontal duct 5 b, while the horizontal duct 5 b is formed integrallywith the casing 30. Specifically, the lower half of the horizontal duct5 b is formed integrally with the bottom wall part 31, while the upperhalf thereof is formed integrally with the body part 32.

As shown in FIG. 18, the inclined duct 5 a is formed to have anapproximately rectangular section at a connected portion with theopening 8 a of the air blowing part 8 in the air blowing unit 3 and anapproximately triangular section at a connected portion with thehorizontal duct 5 b. In the inclined duct 5 a, the air flows whilesmoothly changing its flow direction from the condition that it flowsthrough the rectangular sectional area to the condition that it flowsthrough the triangular sectional area.

In this embodiment, since the horizontal duct 5 b is formed integrallywith the casing 30 but separately from the inclined duct 5 a, theinclined duct 5 a can be easily designed and formed so that the airsmoothly flows therein.

When the air flow is sent from the inclined duct 5 a directly into anintroduction part 39 of the casing 30, the downwardly inclined air flowwill collide with the bottom wall part 31 to disturb or roll upcondensate in the bottom wall part 31. To cope with this, the horizontalduct 5 b is provided immediately before the introduction part 39 in thisinvention. Thus, the air flow that is sent obliquely downwardly from theair blowing unit 3 through the inclined duct 5 a is slightly changedsubstantially horizontally by the horizontal duct 5 b so as to be guidedinto the lower space 39 located below the evaporator 33 through theopening 25 of the air conditioning unit 4. This suppresses the air flowdirecting obliquely downwardly in the lower space 39, minimizes thecollision of the air flow with the bottom wall part 31, and prevents theroll-up of the condensate flowing in the bottom wall part 31.

Particularly, the middle of the bottom wall part 31 is formed with aflat surface portion 31 a which is substantially parallel with thehorizontal duct 5 b. With such a configuration, the air from theintermediate duct 5 flows along the flat surface portion 31 a in thelower space 39 and is changed in flow direction toward the evaporator 33located above the flat surface portion 31 a. This effectively avoids thecollision of the air flow coming into the lower space 39 with thecondensate flow on the inclined surface of the bottom wall part 31toward the drain port 80, and significantly reduces the interference ofthe air flow with the condensate flow.

Further, the air from the air blowing unit 3 to the opening 25 throughthe intermediate duct 5 is sent from the inclined duct 5 a into thelower space 25 of the air conditioning unit 4 while its flow directionis changed substantially horizontally by the horizontal duct 5 b ofsubstantially triangular section. The distribution of air flow rate atthe time shows that a high-speed air in the radially outer side of theair blowing unit 3 flows through the vehicle body rear side of thehorizontal duct 5 b, i.e., the wider sectional area of substantiallytriangular shape in the horizontal duct 5 b, and is sent to the casing30. In other words, a high-speed air flows through the vehicle body rearside, while a relatively low-speed air flows through the narrowersectional area of substantially triangular shape in the horizontal duct5 b, i.e., the vehicle body front side of the horizontal duct 5 b.Therefore, it can be minimized that the air flow interferes with thecondensate flow collected to the drain port 80 located toward thevehicle body front.

Portions of the cooling heat exchanger 33 through which the high-speedair passes are located toward the rear of the vehicle body and arelocated at the higher side of the obliquely inclined heat exchanger 33.The condensate produced in the cooling heat exchanger 33 falls down onthe outer surfaces of the flat tubes 33 a and the corrugate fins 33 b,and flows directly on the bottom surfaces of the corrugate fins and flattubes from the vehicle body rear side to the vehicle body front side ofthe heat exchanger. Otherwise, the condensate flows from the bottomsurfaces of the corrugate fins 33 b to the bottom surfaces of the flattubes 33 a and then flows on the bottom surfaces of the flat tubes 33 afrom the vehicle body rear side to the vehicle body front side of theheat exchanger. Thereby, it can be largely suppressed that thecondensate produced in the cooling heat exchanger is introduced abovethe cooling heat exchanger, i.e., into the heating heat exchanger, bythe high-speed air flow.

The condensate tends to flow into the vehicle body front side of thecooling heat exchanger, i.e., the lower side thereof. The air flow inthis side, however, is at a relatively low rate, and the air flow has alower rate and approximates a flow rate of zero with approach to thefront of the heat exchanger. Therefore, the possibility that thecondensate collected at the front side of the cooling heat exchanger isintroduced into the heating heat exchanger by the air flow is extremelylow.

Further, the cooling heat exchanger has a configuration that allows thecondensate to be promptly discharged, which provides a high heatexchanger effectiveness.

Furthermore, a rib 84 is provided in a standing manner on the bottomwall part 31 of the casing 30 at a position closer to the vehicle bodyfront than the flat surface portion 31 a and along the flowing directionof the air introduced through the intermediate duct 5. The rib 84 canprevent the condensate collected at the drain port 80 from being takeninto the evaporator 33 by the air flow sent to the air conditioning unit4. The condensate, in particular, tends to obliquely downwardly flow onthe bottom surface of the evaporator 33 and then fall down, at thevehicle body front side thereof, to the bottom wall part 31. Therefore,the condensate is most likely to fall down, at the side of theevaporator 33 closer to the vehicle body front than the rib 84, to thebottom wall part 31. The rate of air flow at the side of the bottom wallpart 31 closer to the vehicle body front than the rib 84 is relativelylow, and the interference of the air flow with dropping down andcollection of condensate can be significantly reduced.

Further, an attachment part 85 for attaching the air conditioning unit 4to the dash panel P is provided integrally with the exit 82 of the drainpassage 81. In attaching the air conditioning unit 4, a stud bolt fixedto the dash panel P is inserted into a hole of the attachment part 85,and then the dash panel P is fastened by the stud bolt and a nut.Therefore, when the drain pipe 83 is assembled with the dash panel P,the drain pipe 83 and the dash panel P are free from wobbling to enhancesealing property.

The air conditioning unit 4 is divided into two sections one on another,and the casing 30 consists of the body part 32 forming an upper casingand the side wall part 31 forming a lower casing. Further, the body part32 is divided into right and left portions. The evaporator 33 and theheater core 34 are held sandwiched between the two divided portions ofthe body part 32. This facilitates the assembly of the evaporator 33 andheater core 34 and ensures their retention. Furthermore, in order totake only the evaporator 33 out of the air conditioning unit 4 withoutdisassembling the body part 32, a cover as a separate member is providedon the left side wall 30 a (the air blowing unit side) of the casing 30.The upper half of the horizontal duct 5 b or a cover 81 b for the drainpassage 81 may be provided on the cover, or may be left formed togetherwith the body part 32.

Use of such a divided configuration of the casing eliminates the needfor vertical separation of the bottom wall part 31 and thereforeeliminates fear of leakage of condensate.

Next, the drain passage will be described in detail. In general, for theformation of the drain passage 81 as a hollow body integral with thebottom wall part 31, an elongated core has to be set in molding thebottom wall part 31. It is difficult to form a deep, narrow, elongatedgroove due to difficulties in precise fabrication of the core andsuitable adjustment of the draft angle. Therefore, the formation of anelongated groove has a limitation.

On the contrary, in the present invention, the drain passage 81 isformed by two separate parts, i.e., an elongated groove part 81 a and acover 81 b. The elongated groove part 81 a is formed integrally with thebottom wall part 31, while the cover 81 b is formed integrally with thebody part 32. This enables easy formation of the elongated groove part81 a even if the depth and length thereof are rather large, providesflexibility to the shape and size of the drain passage 81, ensures aspace for storing condensate, and provides the configuration of thespace that can drain off condensate smoothly. Furthermore, there can beincreased design flexibility to the position at which the drain pipe 83is to be attached to the dash panel P.

The heater core 34 is a heating heat exchanger for heating the airhaving passed through the evaporator 33, and is made of tubes and finsstacked in the same manner as in the evaporator 33. In the heater core34, a high-temperature cooling water from the engine circulates in thetubes to heat the air passing through the heater core 34. The heatercore 34 is provided with heater pipes 91, one for introducing the enginecooling water and the other for discharging it. Like each cooler pipefor the evaporator 33, each heater pipe 91 is formed to extend outwardlyfrom the left side wall 30 a of the casing 30 and then extend toward thefront of the vehicle body. Therefore, the heater pipes 91 are alsodisposed in the space between the air conditioning unit 4 and the airblowing unit 3, which provides effective use of this space. Furthermore,since the heater pipes 91 are located above the intermediate duct 5, thefront passenger does not touch these pipes and therefore the attachmentof heat insulators to the heater pipes can be eliminated.

This embodiment is designed so that various heater cores 34 different inheight can be disposed inside of the casing 30. This embodiment, inparticular, is the type provided with a short heater core 34. Therefore,in this embodiment, the casing has a small opening area formed inaccordance with such a short heater core 34, and the other portions ofthe casing are not different from the other types. If a tall heater coreis used, the opening area is formed in accordance with the height of theheater core and the other portions are common to the other types. Inother words, two air mixing dampers 36 and 37 and a partition 40 are notchanged but are common among plural types of casings.

Between the evaporator 33 and the heater core 34, two air mixing dampers(temperature control dampers) 36 and 37 are disposed for controlling thetemperature of a conditioned air. The temperature control of the airmixing dampers 36 and 37 is made by changing the ratio of air havingpassed through the evaporator 33 between the flow rates of a partial airpassing through the heater core 34 and another partial air passingthrough a bypass passage 38 for allowing part of the air having passedthrough the evaporator 33 to bypass the heater core 34.

More specifically, as shown in FIG. 6, the inner space of the casing 30in the air conditioning unit 4 is divided into an evaporator space 41for accommodating the evaporator 33 and a heater core space 42 foraccommodating the heater core 34 by a partition 40 formed integrallywith the inner surface of the casing 30. This partition 40 consists of afront partition 40 a toward the vehicle body front and a rear partition40 b toward the vehicle body rear. In the sectional view of the airconditioning unit 4 looking in the car widthwise direction in FIG. 6,the front partition 40 a extends substantially horizontally and the rearpartition 40 b has the shape of an inverted V. The front and rearpartitions 40 a and 40 b have respective openings 43 and 44 for bringingthe evaporator space 41 into communication with the heater core space42. The openings 43 and 44 are opened and closed by the air mixingdampers 36 and 37, respectively. The rear partition 40 b has also anopening 48 located at the rear of the heater core space 42. The opening48 communicates the bypass passage 38 with the evaporator space 41.

Although not shown, a rib may be provided integrally on the innersurface of the casing 30 between the lower end of the air mixing damper36 in open position and the evaporator 33. Such a rib smoothly guidesthe air flow from the evaporator into the inside of the casing, andprevents the air flow from entering between the lower end of the airmixing damper 36 and the casing inner surface.

The two air mixing dampers 36 and 37 each have a shaft extending in thecar widthwise direction like the inside/outside air switching damper 12.Both ends of the shaft is supported to the casing 30, and the left endof the shaft is coupled via a link mechanism 46 to the output shaft ofan actuator 45 disposed on the left side wall 30 a of the casing 30. Theactuator 45 is fixed to a boss extended from the casing left side wall30 a, like the actuator 15 for the inside/outside air switching damper12.

The two air mixing dampers 36 and 37 are cooperated with each other viathe link mechanism 46, and angularly moved by the actuator 45 from theposition that fully opens the front-side and rear-side openings 43 and44 to the position that fully closes them. In this case, when therear-side air mixing damper 37 is angularly moved to the position thatfully opens the rear-side opening 44, it fully closes the opening 48 atthe upstream end of the bypass passage 38 to pass almost all the airthrough the heater core 34.

The two air mixing dampers 36 and 37 are preferably different inopening/closing timing for precise control, but may optionally have thesame opening/closing timing. In this embodiment, when the air mixingdamper 36 is fully opened, the other air mixing damper 37 is openedhalfway. Then, the air mixing damper 37 is rotated to the full. Whenboth the air mixing dampers 36 and 37 are closed, they are rotated inthe reverse order.

The actuator 45 for the air mixing dampers 36 and 37 also has a coupler49 (shown only in FIGS. 3 and 5) to which a signal line from the airconditioning controller is connected, like the actuator 15 for theinside/outside air switching damper 12.

The evaporator 33 is equipped with a temperature sensor (not shown) fordetecting the surface temperature of the evaporator 33. The heater core34 is equipped with a water temperature sensor (not shown) for detectingthe temperature of the engine cooling water in the heater core 34.Signal lines from these sensors are extended through the left side wall30 a of the air conditioning unit 4 and are connected to the airconditioning controller.

The upper portion of the casing 30 has a plurality of vents 50, 50, . .. formed in an inclined rear surface and defrosting vents 51, 51 formedin an approximately flat surface located at the front of the inclinedrear surface. Further, the upper portion of the casing 30 also has legvents 52 (only right one is shown in FIG. 6) formed in the left andright side walls 30 a and 30 b (as shown in FIGS. 5 and 10),respectively. The vents 50, 50 are connected with vent grilles 53, 53, .. . disposed in the instrument panel 2 as shown in FIG. 4 through ventducts (not shown). Conditioned airs from the vents 50 are mainly blowntoward the upper halves of the passengers. On the other hand, thedefrosting vents 51, 51 are connected with defrosting grilles 54, 54disposed at the front end of the instrument panel 2 through defrostingducts (not shown). Conditioned airs from the defrosting vents 51 areblown toward the inner surface of the front window. The right and leftleg vents 52, 52 are connected to ducts 57, 56 extending downward,respectively. Both the ducts 56, 57 are open in the under surface of theinstrument panel 2 in the vicinities of the driver's and passenger'slegs, respectively, from which conditioned airs are blown toward thedriver's and passenger's legs.

Out of the ducts 56 and 57 connected to the leg vents 52 and 52, thedriver's side duct 56 is provided integrally with the casing 30 to turnfrom the right side wall 30 b of the casing to the rear side wallthereof, has a relatively large sectional area, and therefore serves asa dual-purpose duct for both front and rear seats through which aconditioned air for rear passengers passes together with a conditionedair for front passengers. The front of a portion of the dual-purposeduct 56 corresponding to the casing right side wall 30 b is formed withopenings 55, 55 for blowing out the conditioned air toward the diver'sseat as described above. The bottom of a portion of the dual-purposeduct 56 corresponding to the casing rear wall is formed with connectingparts 58, 58 to which the upper ends of floor ducts (not shown) forguiding the conditioned air toward the rear passengers are connected.

Inside of the casing 30 of the air conditioning unit 4, two blow-outdirection switching dampers 60 and 61 are provided for opening andclosing the vents 50, 51 and 52 to change the blow-out direction of theconditioned air, in the same manner as with the air mixing dampers 36and 37. These dampers 60 and 61 are operated by a link mechanism 62disposed on the left side wall 30 a of the casing 30 of the airconditioning unit 4 and an actuator 63 fixed to the boss on the leftside wall 30 a.

Front-side one of the blow-out direction switching dampers 60 and 61 isa defrosting damper 60 for opening and closing the defrosting vents 51and 51, while rear-side one is a vent damper 61 for opening and closingthe vents 50, 50, . . . The dampers 60 and 61 are cooperated with eachother via the link mechanism 62, and each driven by the actuator 63 toopenings corresponding to a plurality of air blowing modes.Specifically, the air conditioning unit 4 is changeable, according tothe open/closed positions of the two dampers 60 and 61, to any one ofthe air blowing modes including vent mode, defrosting mode, leg mode,and bi-level mode in which air is blown out through the vents 50 and theleg vents 52. The actuator 63 for the blow-out direction switchingdampers 60 and 61 also has a coupler 65 (shown in FIGS. 3 and 5) towhich a signal line from the air conditioning controller is connected,like the actuator 15 for the inside/outside air switching damper 12.

As described above, the link mechanisms 46 and 62 and the actuators 45and 63 for the dampers 36, 37, 60 and 61 in the air conditioning unit 4are together disposed on the left side wall 30 a of the air conditioningunit 4. Therefore, these components can be attached to the airconditioning unit 4 at a time from a single direction in assembling theair conditioning unit 4.

Next, description will be made about the installation of the airconditioner 1 on the vehicle body. Attachment parts for the air blowingunit 3 and the air conditioning unit 4 will be first described. The airblowing part 8 of the air blowing unit 3 is provided at the right andleft sides with a pair of attachment legs 68 and 68. The filteraccommodation part 21 is provided with an attachment leg 69 extendingfrom the right side wall toward the right side of the vehicle body. Onthe other hand, attachment parts for the air conditioning unit 4includes an attachment part 85 on an attachment leg 70 formed integrallywith the drain 35, and attachment parts on a pair of attachment legs 71and 71 provided at the right and left side of the top of the casing 30.

The attachment legs 68, 69, 70 and 71 of the air blowing and airconditioning units 3 and 4 are formed with through holes, respectively.The dash panel P is provided with stud bolts (not shown) attached toalign themselves with the through holes. As shown in FIG. 12, the dashpanel P is formed with through holes 102 corresponding to the respectivepositions where the cooler pipes 90, the heater pipes 91 and the drainpassage 81 are disposed. With this configuration, when the airconditioner 1 is positioned with respect to the vehicle body to insertthe stud bolts into the corresponding through holes in the attachmentparts 68-71 of the units 3 and 4, the cooler pipes 90 and the heaterpipes 91 are presented to the engine room through the through holes 102in the dash panel P. In this state, nuts are screwed on the stud boltsthereby firmly fixing the air conditioner 1 to the vehicle body.Furthermore, the cooler pipes 90 and the heater pipes 91 are connectedto corresponding pipes in the engine room, while the drain pipe 83 isconnected to a final drain pipe. The connection work for all the cooler,heater and drain pipes 90, 91 and 83 can be carried out at close handfrom the engine room side, which reduces the number of processes.

Next, the sealing mechanism of the air conditioner 1 and the dash panelP will be described. A dash insulator D is attached to the passenger'sroom side of the dash panel P. Cushion sealing members 101 are attachedto the outer peripheries of the cooler, heater and drain pipes 90, 91and 83. In this embodiment, a single sealing member 101 is attached tothe heater pipes 91 and one of the cooler pipes 90. Another two sealingmembers 101 are attached individually to the other cooler pipe 90 andthe drain pipe 83.

The dash panel P is formed with through holes 102 for passing thecorresponding pipes 90, 91 and 83 therethrough. The dash insulator D isformed with openings 103 larger in diameter than the through holes 102and smaller in diameter than the recesses in the bracket 92. With thisconfiguration, in assembly, the bracket 92 is pressed against the dashinsulator D to seal the openings 103 and the sealing members 101 arepressed against the dash panel P to seal the through holes 102 in thedash panel P. Such a double sealing structure increases sealingproperties.

Furthermore, in the air conditioner for an automobile according to thisembodiment, an air from the air blowing unit 3 is sent to the airconditioning unit 4 through the intermediate duct 5. The link mechanisms46 and 62 and actuators 45 and 63 for the air mixing dampers 36 and 37and the air blow-out direction switching dampers 60 and 61 in the airconditioning unit 4 are attached to the air blowing unit side of the airconditioning unit casing 30. The actuator 15 for the inside/outside airswitching damper 12 in the air blowing unit 3 is attached to the airconditioning unit side of the air blowing unit casing 6. Therefore, thelink mechanisms 46 and 62 and the actuators 15, 45 and 63 can beaccommodated in a dead space located above the intermediate duct 5,thereby reducing the size of the air conditioner 1 and the installationspace therefore. Furthermore, the link mechanisms 46 and 62 and theactuators 45 and 63 can be assembled with the air conditioning unitcasing 30 from a single direction. This reduces the number of assemblyprocesses for the air conditioning unit 4.

The couplers 17, 27, 49 and 65, which connect the actuators 15, 45 and63 for the dampers 12, 36, 37, 60 and 61, the temperature sensor for theevaporator 33, the water temperature sensor for the heater core 34 andthe control circuit 26 for the air blowing fan 23 with the airconditioning controller, are collected in the space between the airblowing unit 3 and the air conditioning unit 4. This reduces the numberof processes for assembly of the air conditioner 1 with the vehiclebody.

The right side wall 30 b (the driver's side) of the air conditioningunit 4 is not provided with the link mechanisms 46 and 62 and theactuators 45 and 63, which increases the sectional area of the driver'sside duct 56 and the design flexibility to the duct 56. This increasesthe usefulness of the right side wall 30 b of the air conditioning unit4. In other words, the amount of air blow for the driver and passengerscan be ensured sufficiently by the duct 56 alone. In addition, a spacein the vicinity of the driver's legs can be increased.

FIGS. 19 to 23 show an air conditioner according to another embodimentof the present invention. This embodiment is directed to an airconditioner for a left-hand drive car in which the air conditioning unit4 is placed substantially in the car widthwise middle of the instrumentpanel 2 and the air blowing unit 3 is placed to the front-passenger'sseat side of the air conditioning unit 4 (toward the right of FIG. 19).Description will be made about only different parts from the firstembodiment, and will be omitted about the other parts.

Two heater pipes 91 are juxtaposed one above the other like the firstembodiment, while two cooler pipes 90 are disposed laterally andcollected by a block 100. The vertical plane that divides the bracket 92into the fixed and detachable brackets 92 a and 92 b runs through thevertical center lines of the heater pipes 91 and the center line of theblock 100. The seal plate 93 a is assembled into the fixed anddetachable brackets 92 a and 92 b by being slidingly inserted into themfrom below. The seal plate 93 a has recesses whose diameters correspondto the outer diameters of the two cooler pipes 90 and which surround twothirds of the pipes to simultaneously fix the two cooler pipes 90. Thisincreases the retention to the cooler pipes 90 when the seal plate 93 ais inserted into the brackets.

The outer diameters of the cooler and heater pipes 90 and 91 hereinreferred to may be actual outer diameters thereof or, if fitting memberssuch as cushion members or heat insulators are fitted onto the pipes,may be outer diameters of the fitting members or the compressed fittingmembers.

FIG. 24 shows an exemplary attachment structure of the expansion valvebox 96. As shown in FIG. 22, the expansion valve box 96 is disposed inthe outside wall of the body part 32 in an embedded manner. Typically,when the expansion valve box 96 is assembled with the casing 30 byconnecting it to the evaporator 33, a butyl rubber member or the like isadhered to an exposed portion of the expansion valve box 96 to cover theexposed portion, thereby preventing exposure to the outside air andcondensation. In this embodiment, however, an extended wall 30 a isformed integrally with the casing 30 to surround the expansion valve box96. The expansion valve box 96 is first accommodated in the extendedwall 30 a, the extended wall 30 a is covered with a cover 30 b in closecontact, and the extended wall 30 a and the cover 30 b are fastened witha bolt. In this manner, the expansion valve box 96 can be prevented frombeing exposed to the outside air. At the removal of the expansion valvebox 96, the cover 30 b need only be detached. On the other hand, at theattachment of the expansion valve box 96, it is necessary only toaccommodate the expansion valve box 96 in the extended wall 30 a andthen insert the cover 30 b onto the extended wall 30 a again. Thisprovides easy attachment and detachment of the expansion valve box 96.Further, no sealing member such as a butyl rubber is consumed for eachattachment, which results in reduced cost and improved environment.

In the embodiment of FIG. 22, two cooler pipes connected to theexpansion valve box are provided to extend substantially at a rightangle from each other. Two cooler pipes, however, may be extended in thesame direction. In particular, two cooler pipes may be arranged towardthe cover 30 b and extended in a direction in which the cover isinserted onto and pulled out of the expansion valve box. Further, theextended wall may be higher than the height of the expansion valve tocover the expansion valve. Alternatively, the extended wall may be lowerthan the height of the expansion valve and the cover may have a flangefor covering the periphery of the expansion valve.

Furthermore, in the above embodiments, the intermediate duct 5 has aninclined duct 5 a as a separate member and a horizontal duct 5 b formedintegrally with the casing 30. However, the inclined and horizontalducts 5 a and 5 b may be integrally formed to separate them from thecasing 30.

The above embodiments are directed to air conditioning units of the typethat the evaporator is inclined in a car lengthwise direction. However,the present invention is applicable, depending upon components to beprovided, to the type that the evaporator is inclined in a car widthwisedirection.

INDUSTRIAL APPLICABILITY

As can be seen from the above, vehicle air conditioners of the presentinvention is suitable for downsizing.

1. A vehicle air conditioner comprising: an air conditioning unitdisposed substantially in an inside middle portion of an instrumentpanel in a widthwise direction of a vehicle body, said air conditioningunit including a casing; an air blowing unit disposed to afront-passenger's side of the air conditioning unit; an intermediateduct for ducting an air from the air blowing unit to the airconditioning unit; a cooling heat exchanger and a heating heat exchangerdisposed in the air conditioning unit; cooler pipes connected to thecooling heat exchanger and heater pipes connected to the heating heatexchanger are arranged to extend from the same side of the airconditioning unit in the widthwise direction of the vehicle; a spaceprovided under the cooling heat exchanger in the casing into which airfrom the intermediate duct is introduced; a drain part having a drainpassage integrally formed with a bottom wall part of the casing andprojecting out from a side wall part of the air conditioning unit on theair blowing unit side, with an exit of the drain part being locatedcloser to the front of the vehicle body than the intermediate duct;wherein said air conditioner allows the air introduced from theintermediate duct into the air conditioning unit to pass through thecooling and heating heat exchangers disposed in the air conditioningunit to produce a conditioned air.
 2. The vehicle air conditioner asdefined in claim 1, wherein the cooling heat exchanger is inclineddownwardly toward a front portion of the vehicle body.
 3. The vehicleair conditioner as defined in claim 2, wherein the exit of the drainpart is connected with a drain pipe extending toward a front portion ofthe vehicle body.
 4. The vehicle air conditioner as defined in claim 3,wherein the air conditioning unit includes an attachment part forattachment to the vehicle body, said attachment part being integrallyformed with said drain part close to the exit of said drain part.
 5. Thevehicle air conditioner as defined in claim 3, further comprisingthrough holes formed in a dash panel of the vehicle body, wherein saiddrain pipe is inserted into said through holes.
 6. The vehicle airconditioner as defined in claim 5, wherein the drain pipe extends in adirection approximately orthogonal to the dash panel.
 7. The vehicle airconditioner as defined in claim 1, wherein the casing of the airconditioning unit is divided into an upper and a lower part, said lowerpart being a bottom wall part placed under the cooling heat exchangerand the upper part being a body part above the bottom wall part; saidbody part being divided into a driver seat side member and a passengerseat side member; and a heater pipe is supported by the passenger seatside member.
 8. The vehicle air conditioner as defined in claim 1,wherein the casing of the air conditioning unit is divided into an upperand a lower part, said lower part being a bottom wall part placed underthe cooling heat exchanger and the upper part being a body part abovethe bottom wall part; said body part being divided into a driver seatside member and a passenger seat side member; and the drain part iscomposed of an elongated groove part formed at the bottom wall part soas to be open upward and a cover is integrally formed with the body partcovering the elongated groove part.
 9. The vehicle air conditioner asdefined in claim 1, wherein the drain part is positioned at the lowestlevel in the bottom wall part of the casing of the air conditioningunit, and a portion, opposite to the drain part and on the driver seatside, is positioned at the highest level; and said bottom wall part hasan inclined surface inclining downward from said portion on the driverseat side toward the drain part.
 10. The vehicle air conditioner asdefined in claim 9, wherein said intermediate duct has an inclined partinclining downward from the air blowing unit toward the air conditioningunit and a direction switching part connecting the inclined part and theair conditioning unit; and a bottom face of the direction switching partis substantially horizontal.
 11. The vehicle air conditioner as definedin claim 10, wherein a cooler pipe and a heater pipe project out from aside wall part of the air conditioning unit on the air blowing unit sideand bend to extend toward the front of a vehicle; and the cooler pipe,the heater pipe and the drain part are positioned close with each other.12. The vehicle air conditioner as defined in claim 1, wherein a sidewall part of the casing of the air conditioning unit on the air blowingunit side has an opening to which the intermediate duct is connected;and the shape of the opening is an approximate triangle with two sidesgetting narrower as they come close to the front of a vehicle.